Aircraft propeller



E R R u c G G AIRCRAFT PROPELLER Filed Dec. 26, 1928 2 Sheets-Sheet l I NVEN TOR.

ATTORNEY. I

May 13, 1930. 5. G. CURRIE AIRCRAFT PROPELLER 2 Sheets-Sheet 2 Filed Dec. 26, 1928 INVENTOR. G. G. CURR/E.

ATTORNEY.

Patented May 13, 1930 UNITED. STATES PATENT OFFICE GAIL G. CURRIE, LOS ANGELES, CALIFORNIA, ASSI GNOR OF ONE-HALF TO E.

' RICHARD JUST, OF LOS ANGELES, CALIFORNIA AIRCRAFT PROPELLER Application filed December 26, 1928. Serial No. 328,336.

This invention relates to improvements in propellers. I

The general object of the invention is to provide an improved propeller for use on aircraft.

A more specific object of the invention is to provide an aircraft propeller wherein the efficiency of the pro eller is increased.

Another object 0 the invention is to provide a propeller including means for forcing air towards the center of the propeller.

A specific object of the invention is to provide a propellerhaving a plurality of vanes on the lade which are adapted to force air towards the center of the propeller.

An additional object of my invention is to provide a propeller including blades having vanes thereon so arranged that the vanes on one blade intercept the air currents formed by the vanes on the other blades. IA

Other objects and the advantages of this invention will be apparent from the following descriptiontaken in connection with the accompanying drawings wherein:

Fig. 1 is a front view of one form of my improved propeller.

Fig. 2 is a side elevation of the propeller shown in Fig. 1. J A Fig. 3 is an enlarged section taken on line 3g Of 2.

Fig. 4 is a front face .view 015 a modified form of propeller.

Fig. 5 is an enlarged transverse section through one of the blades of the propeller shown in Fig. 4.

6-6 ofFig. 5.

Fig. 7 1s an enlarged fragmentary. top plan view of a flat development of one of the blades of'the and v Fig. 8 is a diagrammatic view showing the manner in which the air currents from the vanes on one of the propeller blades are intercepted by the vanes on the other blade;

Referrin to the drawings by reference characters have. indicate my improved propeller enerally at 10. As shown this pro- Fig. 6 is an enlarged section taken on line they propeller shown in Fig. 4-

eller inc udes a. central body portion 12 iiavin'g blades '13 and 14 extending therefrom.

in opposite directions and is provided with a hub 15 for securing it to the drive shaft of an engine (not shown). The blades 13 and 14 are shown as converging outwardly from their juncture with the body portion 12 and are formed with reverse pitches relative to axis of rotation of the hub 15. The

longitudinal centerlines 13' and 14 of the blades 13 and 14 respectively are spaced on opposite sides of the center of the hub 15 so that when the propeller rotates the inner leading edge 16 of each blade is in advance of the inner trailing edge 17 of each opposite bla'de. i

The longitudinal sides 18 of the body portion are formed. at an angle relative to the longitudinal centerline and extend from the inner edges of one blade to theinner edges of the other blade and the topsurface of the body portion is diagonallytapered on each side from the high point of bladeto the low point of the other blade as indicated at 19.

Each of the blades 13 and 14 are provided on their working faces with a plurality of spaced vanes 20 which may be integral with the blades and may extend the full length of each blade as shown in Figs. 1 and 2, or which may extend for only a part of the length of each blade as shown in Fig. 4 (to be presently described). so

The vanes 20 are inclined towards the hub 15 and are curved inwardly from the leading edge of the blades towards the center of the propeller. The center of the curves of the vanes on each blade are positioned to one side of the centerline of the blades upon which are located in such a manner that the trailing edge of the vanes are closer to the center 01. the propeller than the leading ed e whereupon w en the ropeller rotates t e vanes force a current 0 air towards the cen-' ter of the propeller, thereby obliterating the dead air space which usually occurs at the center of ropellers.

In Fi I have shown a preferred arrangement'o the vanes wherein the vanes 22 nearest the center of the propeller are so arranged that the trailing edge 23 of eachsuccessive vane is spaced further from the trailing edge of each preceding vane and all the leading 100 edges 24are spaced an equal distance apart. Thus it will be seen that the vanes of the pro peller crowd the air towards the center.

towards the center of the propeller and the pitch of the blades propels the air away from the propeller to increase the working efl'iciency.

In Figs. 4, 5 and 6 I have indicated-a modified form of my improved propeller generally at 30. As shown this propeller is constructed similar to the airplane propellers now in general use and comprises a central hub 31 having oppositely disposed blades 32 extending therefrom. These blades are provided with a pitch and are preferably formed concave on the" bottom and convex on the top as clearly shown in Fig. 5.

Each of the blades 32 are provided with a plurality of spaced vanes 33 on their working surfaces which are shown as extending to a point intermediate the length of each blade but which may extend the full length of the blade similar to the vanes shown on the propeller in Fig. 1.

The vanes 33 are inclined towards the center of the propeller and are shown as curved similar to the vanes shown in Fig. 7 and func tion in the same manner as previously described in connection with the propeller 10.

The top edge of the blades 33 are also preferably slightly curved as indicated at 34 in Fig. 6 so that the air thrown outward from the propeller blades will be directed centerward.

Although I have shown two forms of propellers equipped with my invention it will be apparent the vanes may be arranged on any type of propeller and may be arranged to extend the full length of the propeller blades or any part of the length thereof without departure from the features of my invention. Moreover my invention may be applied to two bladed propellers or propellers having three or more blades with equal facility.

From the foregoing description it'will be apparent that I have provided a novel propeller which is simple in construction and highly efiicient in use.

Having thus described my invention, I claim:

1. In a propeller, a central body portion, a pair of blades extending from said body, the longitudinal axis of said blades being spaced on opposite sides of the center of rotation, said blades each tapering outwardly towards bod the longitudinal centerline of said i bla es being spaced on opposite sides of the center of said body and the inner leading edge of said blades being spaced further from the center of said body than the trailing edge of the opposite blade and a plurality of upstanding vanes on the working face of each of said blades.

3. In a propeller, a central body portlon, a

pair of opposltely disposed pitched blades extending from said body, the longitudinal centerline of said blades being spaced on opposite sides of the center of said body and the inner leading edge of each blade being spaced further from the center of said body than the trailing edge of the opposite blade, a plurality of upstanding transverse vanes on the working face of each of said blades, said vanes being inclined towards the center of said propeller and being curved the curve of said vanes being so arranged that the leading edge of each vane is spaced further from the center of said propeller than the trailing edge.

In testimony whereof, I hereunto aflix my signature.

' GAIL G. CURRIE. 

